[cxx-interop] Disable rvalue references. We don't support them correctly (leading to lifetime issues). We are missing a consuming.

Author: zoecarver

lib/ClangImporter/ImportType.cpp

@@ -2347,12 +2347,17 @@ ClangImporter::Implementation::importParameterType(
                  dyn_cast<clang::TemplateTypeParmType>(paramTy)) {
     swiftParamTy = findGenericTypeInGenericDecls(
         *this, templateParamType, genericParams, attrs, addImportDiagnosticFn);
-  } else if (auto refType = dyn_cast<clang::ReferenceType>(paramTy)) {
+  } else if (auto refType = dyn_cast<clang::ReferenceType>(paramTy)) {    
     // We don't support reference type to a dependent type, just bail.
     if (refType->getPointeeType()->isDependentType()) {
       return None;
     }
 
+    // We don't support rvalue reference types, just bail.
+    if (refType->isRValueReferenceType()) {
+      return None;
+    }
+
     paramTy = refType->getPointeeType();
     if (!paramTy.isConstQualified())
       isInOut = true;

test/Interop/Cxx/reference/reference-irgen.swift

@@ -45,19 +45,3 @@ public func setCxxConstRef() {
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main14setCxxConstRefyyF"()
 // CHECK: call void @{{_Z20setConstStaticIntRefRKi|"\?setConstStaticIntRef@@YAXAEBH@Z"}}(i32* %{{.*}})
-
-public func setCxxRvalueRef() {
-  var val: CInt = 21
-  setStaticIntRvalueRef(&val)
-}
-
-// CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main15setCxxRvalueRefyyF"()
-// CHECK: call void @{{_Z21setStaticIntRvalueRefOi|"\?setStaticIntRvalueRef@@YAX\$\$QEAH@Z"}}(i32* %{{.*}})
-
-public func setCxxConstRvalueRef() {
-  let val: CInt = 21
-  setConstStaticIntRvalueRef(val)
-}
-
-// CHECK: define {{(protected |dllexport )?}}swiftcc void @"$s4main20setCxxConstRvalueRefyyF"()
-// CHECK: call void @{{_Z26setConstStaticIntRvalueRefOKi|"\?setConstStaticIntRvalueRef@@YAX\$\$QEBH@Z"}}(i32* %{{.*}})

test/Interop/Cxx/reference/reference-module-interface.swift

@@ -7,9 +7,7 @@
 // CHECK: func getConstStaticIntRvalueRef() -> UnsafePointer<Int32>
 // CHECK: func setStaticInt(_: Int32)
 // CHECK: func setStaticIntRef(_: inout Int32)
-// CHECK: func setStaticIntRvalueRef(_: inout Int32)
 // CHECK: func setConstStaticIntRef(_: Int32)
-// CHECK: func setConstStaticIntRvalueRef(_: Int32)
 // CHECK: func getFuncRef() -> @convention(c) () -> Int32
 // CHECK: func getFuncRvalueRef() -> @convention(c) () -> Int32
 // CHECK: func refToTemplate<T>(_ t: inout T) -> UnsafeMutablePointer<T>
@@ -18,3 +16,5 @@
 // CHECK-NOT: refToDependent
 // CHECK-NOT: refToDependentParam
 // CHECK-NOT: dontImportAtomicRef
+// CHECK-NOT: setStaticIntRvalueRef
+// CHECK-NOT: setConstStaticIntRvalueRef

test/Interop/Cxx/reference/reference-silgen.swift

@@ -51,21 +51,3 @@ func setCxxConstRef() {
 // CHECK: sil hidden @$s4main14setCxxConstRefyyF : $@convention(thin) () -> ()
 // CHECK: [[REF:%.*]] = function_ref @{{_Z20setConstStaticIntRefRKi|\?setConstStaticIntRef@@YAXAEBH@Z}} : $@convention(c) (@in_guaranteed Int32) -> ()
 // CHECK: apply [[REF]](%{{[0-9]+}}) : $@convention(c) (@in_guaranteed Int32) -> ()
-
-func setCxxRvalueRef() {
-  var val: CInt = 21
-  setStaticIntRvalueRef(&val)
-}
-
-// CHECK: sil hidden @$s4main15setCxxRvalueRefyyF : $@convention(thin) () -> ()
-// CHECK: [[REF:%.*]] = function_ref @{{_Z21setStaticIntRvalueRefOi|\?setStaticIntRvalueRef@@YAX\$\$QEAH@Z}} : $@convention(c) (@inout Int32) -> ()
-// CHECK: apply [[REF]](%{{[0-9]+}}) : $@convention(c) (@inout Int32) -> ()
-
-func setCxxConstRvalueRef() {
-  let val: CInt = 21
-  setConstStaticIntRvalueRef(val)
-}
-
-// CHECK: sil hidden @$s4main20setCxxConstRvalueRefyyF : $@convention(thin) () -> ()
-// CHECK: [[REF:%.*]] = function_ref @{{_Z26setConstStaticIntRvalueRefOKi|\?setConstStaticIntRvalueRef@@YAX\$\$QEBH@Z}} : $@convention(c) (@in_guaranteed Int32) -> ()
-// CHECK: apply [[REF]](%{{[0-9]+}}) : $@convention(c) (@in_guaranteed Int32) -> ()

test/Interop/Cxx/reference/reference.swift

@@ -51,20 +51,6 @@ ReferenceTestSuite.test("pass-const-lvalue-reference") {
   expectEqual(22, getStaticInt())
 }
 
-ReferenceTestSuite.test("pass-rvalue-reference") {
-  expectNotEqual(52, getStaticInt())
-  var val: CInt = 52
-  setStaticIntRvalueRef(&val)
-  expectEqual(52, getStaticInt())
-}
-
-ReferenceTestSuite.test("pass-const-rvalue-reference") {
-  expectNotEqual(53, getStaticInt())
-  let val: CInt = 53
-  setConstStaticIntRvalueRef(val)
-  expectEqual(53, getStaticInt())
-}
-
 ReferenceTestSuite.test("func-reference") {
   let cxxF: @convention(c) () -> Int32 = getFuncRef()